Metal complex catalysts with hydrazide ligands have in generally been described as oxidation catalysts, for example, in DE 196 39 603. However, the compounds disclosed are not active enough.
In WO 2009/124855 metal complex compounds having hydrazide ligands, preferably with electron withdrawing groups adjacent to the acyl group are described. The respective acylhydrazone ligands and their use are also described. The instant compounds differ from those described in WO 2009/124855 by being substituted with a specific cyclic ammonium group adjacent to the acyl group. This specific substitution pattern ensures a significantly higher bleaching activity as compared to prior art complexes or ligands.